Your best bet is probably to skip the lower rail. I think 16 inches is way too low, you'd have canes on the ground. Even the top rail could be a little higher, but will probably work. There's definitely not enough room for 4 arms, barely enough for 2.

Your posts are 11 feet apart, right? You could plant 1 vine at each post and extend the arms half way to the next post (5.5 feet in each direction would be a pretty good length).

Snow cover should not hurt the vines, it will actually insulate them somewhat from the cold. The only question I would have is, do they use any chemicals (or salts) on the road?

I don't grow seedless concord, but everyone that I have talked to that does says not to waste your time. I have heard the yield is small and the taste is not the best. You might want to consider getting a different kind or even regular, seeded concord.

Thanks! That's what I was thinking. The city does use a sand salt mix. Do you think it would be enough to effect them? There will be about 8 feet between the road edge and base of grapes. I plan to plant on the yardside of the fence.

Seedless concord is not as hardy as seeded, but my mom tried some of the grapes at a friend's house a while back and loved the seedless. She bought two this year and is going to try them with her regular concords.

I like your idea of a split rail fence and might try something like that myself, along the back. I think I'll try concord and valiant, in case concord doesn't get ripe in time :)

Well, we have a small vineyard with a T type trellis. Vines will pretty much go where you tell them. There are no rules. In Santorini Greece, they wrap vines around and around and up and up making a big basket. They don't use a trellis. The vine is it's own trellis.

Our cordon wire is 22" off the ground, and the top fruiting wire is about 48" high. In between those wires is another wire. Vines do need something to climb on.

Here is a link to vines in the national registry. Click on any vine, and you will learn it's parentage, whether it's table or wine, and what country it originated. If I were you, I'd look for varieties that thrive in the cold weather. The list also gives you nurseries where you can purchase the varieties.

I think grape vines would look great on your fence!

Here is a link that might be useful: National Grape Registry